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Faint at the Sight of Blood? It Could be Vasovagal Syncope

Does your child’s birth story include the part where your spouse passed out during your epidural? One minute they’re by your side, holding your hand, the next, they’re on the floor.

Most of us have felt a bit uneasy and even faintish from time to time—whether it’s the sight of blood or needles. However, if you’ve ever seen someone faint—even your loving spouse during childbirth—you know it can be a scary experience.

But what causes people to inexplicably pass out? There’s actually a medical name for it: vasovagal syncope.

Vasovagal syncope, also called neurocardiogenic syncope or reflex syncope, is a condition that is caused by not getting enough blood flow to your brain, causing you to lose consciousness or pass out.

Although this condition might sound scary, vasovagal syncope is one of the most common and benign forms of fainting. It most often affects children and young adults, but it can happen at any age.

To better understand vasovagal syncope, we spoke with Arnold Pfahnl, MD, a cardiologist and electrophysiologist with Banner Health and the CardioVascular Institute of North Colorado Cardiology Clinic, who treats patients with this condition.

What is vasovagal syncope?

“Vasovagal syncope occurs when not enough blood gets to the brain for a limited period,” Dr. Pfahnl said. “The brain is triggered to send nerve impulses to the heart and blood vessels that cause a limited period of low blood pressure or drop in blood pressure due to either slow heart rates or opening of the blood vessels or both."

To break it down: vaso are our blood vessels; vagal refers to the vagus nerve, which plays a role in controlling the speed and force of our heartbeat; and syncope means the loss of consciousness.

When stress is put upon the vagus nerve, it can short circuit causing our blood vessels to widen or tighten affecting the blood flow to our brains. That’s why one minute you could be totally fine, the next you’re not. Upon suffering this condition, you will often fall to the floor. When you fall, gravity takes effect allowing blood to reach the brain again and you rapidly regain consciousness.

What causes vasovagal syncope?

Several triggers can cause vasovagal syncope, but it can affect men and women differently.

“Women tend to have more symptoms and different triggers than men,” Dr. Pfahnl said. “Once diagnosed, women seem to have more frequent episodes than men as well.”

The most common causes include stress from fear or pain, but can include:

  • Standing for long periods of time
  • Heat exposure and exhaustion
  • The sight of blood or needles
  • Dehydration
  • Intense pain or emotion

Less common causes include:

  • Urinating
  • Swallowing
  • Coughing
  • Straining during a bowel movement

How is vasovagal syncope treated?

The good news is that vasovagal syncope is more of a nuisance than dangerous. But if you have this condition, you’ll definitely want to get it evaluated and treated appropriately.

“Treatment focuses on recognizing and avoiding triggers,” Dr. Pfahnl said. “Educating yourself regarding triggers can help provide relief from anxiety and worry and help prevent further episodes.”

Some other suggestions on preventing vasovagal syncope or fainting include:

  • Wearing compression stockings
  • Maintaining adequate hydration
  • Eating a higher salt diet
  • Moderate exercise

Occasionally, your doctor may recommend medication and certain therapies for those who suffer from recurrent vasovagal syndrome.

“In very rare cases, where patients have prolonged and very slow heart rates, a pacemaker may be recommended but it isn’t widely practiced,” Dr. Pfahnl said.

Is vasovagal syncope ever dangerous?

Vasovagal syncope is generally not dangerous but can be if it occurs at certain times.

“With severe forms of vasovagal syncope, where there is no warning sign of an impending episode, it can be dangerous if you fall and hurt yourself, or if you are driving,” Dr. Pfahnl said. “If you have chronic syncope or have no warning signs before you faint, your doctor may advise against driving.”

Another form of syncope, known as cardiac syncope, is caused by various heart conditions, such as cardiac arrhythmias like AFib, tachycardia and heart valve disorders. Cardiac syncope can increase the risk for sudden cardiac death, so it’s important your doctor is consulted.

Overall outlook

While vasovagal syncope is a common condition, if you’ve ever experienced an episode of vasovagal syncope, especially more than one episode, you should talk to your doctor to help rule out other conditions and determine the best course of treatment for you.

Are you experiencing episodes of syncope? Schedule an appointment with one of our Banner Health specialists. Visit bannerhealth.com.

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